System.IO.FileLoadException: Could not load file or assembly 'OpenTracing' (.NET Standard 2.0)

I have added as reference to the .NET Standard 2.0 class library and build the solution successful. But while executing .NET Standard class library I got following exception.

 ---> System.IO.FileLoadException: Could not load file or assembly 'OpenTracing, Version=0.12.1.0, Culture=neutral, PublicKeyToken=61503406977abdaf'. The located assembly's manifest definition does not match the assembly reference. (0x80131040)

File name: 'OpenTracing, Version=0.12.1.0, Culture=neutral, PublicKeyToken=61503406977abdaf'
---> System.IO.FileLoadException: The located assembly's manifest definition does not match the assembly reference. (0x80131040)

I have installed following OpenTracing nuget package for .NET in linux.

/root/.nuget/packages/opentracing/0.12.0/lib/netstandard2.0/OpenTracing.dll
/root/.nuget/packages/opentracing/0.12.0/lib/netstandard2.0/OpenTracing.pdb
/root/.nuget/packages/opentracing/0.12.0/lib/netstandard2.0/OpenTracing.xml

Am i missing something here to load "OpenTracing" assembly as a reference?

Why "Open Tracing" assembly is not loaded even i have in stalled it?

Thanks in advance.